I used the fix you recommended and am still getting the following error:
Error using sym>convertExpression (line 2576) Conversion to 'sym' returned the MuPAD error: Error: ']' expected [line 1, col 11]
Error in sym>convertChar (line 2487) s = convertExpression(x);
Error in sym>convertCharWithOption (line 2470) s = convertChar(x);
Error in sym>tomupad (line 2224) S = convertCharWithOption(x,a);
Error in sym (line 111) S.s = tomupad(x,'');
Error in sym/horzcat (line 17) args{k} = sym(args{k});
Error in dsolve>mupadDsolve (line 253) sys_str = ['[' sys{1:end-1} ']'];
Error in dsolve (line 153) sol = mupadDsolve(args, options);
Error in LHeat (line 4) an = dsolve(equal,subs(sym('g(0)=Tstart'),'Tstart',Tstart),'t');
Error in CalibratedPyro1018A (line 109) lump(i+1)=LHeat(qin,rho,v,cp,h(i),As,lump(i),Tinf,1); % Finding the temperature